1. Technical Field
Disclosed apparatus, systems, and methods relate to calibrating microphones in an electronic system.
2. Description of the Related Art
Electronic devices often use multiple microphones to improve a quality of measured acoustic information and to extract information about acoustic sources and/or the surroundings. For example, an electronic device can use signals detected by multiple microphones to separate them based on their sources, which is often referred to as blind source separation. As another example, an electronic device can use signals detected by multiple microphones to suppress reverberations in the detected signals or to cancel acoustic echo from the detected signals.
When processing signals detected by multiple microphones, electronic devices often assume that the microphones have the same magnitude sensitivity and phase error. Unfortunately, microphones often do not have the same magnitude sensitivity and phase error, even when the microphones were created using the same process. Such a process variation is more pronounced in cheap microphones often used in consumer electronics such as smart phones. Because a moderate variance in the magnitude sensitivity and/or phase error can cause a significant error in the above-mentioned applications, there is a need in the art to provide apparatus, systems, and methods for calibrating microphones.